Visitors to the Maryland Science Center's "SpaceLink" exhibit had an extra source to answer questions about Mars rover Curiosity on Monday -- a scientist who helped develop one of its instruments.

Jennifer Stern, a space research scientist at the NASA Goddard Space Flight Center in Greenbelt, was on hand with a model of Curiosity and a life-size version of one of its wheels. Stern is part of a team that has worked on the Sample Analysis at Mars, or SAM, a set of three instruments that will be used to analyze rock and soil samples from the Martian surface.

The aim, Stern said, is to determine whether the Red Planet was ever a place where life could have existed. Scientists expect to find rocks like sandstone and mudstone -- varieties that on Earth are created because of the presence of water and sediment, she said.

"To be able to confirm that as much as we can is huge," Stern said.

SAM is one of 10 instruments on the rover, which landed on the surface of Mars at 1:32 a.m. Monday. The one-ton vehicle is on a two-year investigation managed by the NASA Jet Propulsion Laboratory in California.

SAM contains tools to test samples for organic compounds and other elements common in life on Earth.

Some science center visitors were eager to learn more about Curiosity. Dominic Crino and Sam Keeler, both 12, came from Severna Park to visit the science center and were excited to find more information about the rover there.

"I think we need Mars rocks, not just moon rocks," Keeler said.

Stern welcomed enthusiasm over the mission. While manned missions to space inspire people, information Curiosity gathers could help make significant advancements in understanding, she said.

"It's one of those events that gets people excited again," Stern said.